A preparation process of high performance 5083 aluminum alloy sheet was proposed. The process is severe plastic deformation process of alternate ring-groove pressing and torsion based on cyclic stress state under warm conditions. The results show that when the temperature is 200 °C, the grain refinement effect after secondary deformation is the best, and the average grain size is refined from 24 to 12.5 μm. When the temperature is 300 °C, the mechanical properties of the sheet after one deformation are the best. Compared with those of the original sheet, the tensile strength (397 MPa) and breaking elongation (28.3%) are increased by 30% and 60%, respectively. The second phase particles and recrystallized grains improve the strength of the material by second phase strengthening and fine grain strengthening. The equiaxed recrystallized grains improve the plasticity and toughness of the material.